Drill pipe protector

ABSTRACT

A novel latching mechanism is provided for a drill pipe protector of the split ring type. The latch mechanism includes hook members located on the either side of the &#39;&#39;&#39;&#39;split,&#39;&#39;&#39;&#39; which are secured in place around a drill string by a C-clip which slides longitudinally. Tabs on each end of the split permit ready longitudinal alignment of hook members for sliding of the C-clip into place.

United States Patent Napper 14 1 Jan. 9, 1973 541 DRILL PIPE PROTECTOR 3,051,532 8/1962 Collett ..308/4 A Inventor: Mason Wayne pp Lafayette, 1,965,730 7/1934 W1ll1ams ..308/4 A FOREIGN PATENTS OR APPLICATIONS 1 AssigneeI Galaxie Manufacturing 81 Sales 701,557 12/1953 Great Britain ..308/4 A lnc., Lafayette, La. [22] Filed: No 15, 1971 Primary ExaminerMilton Kaufman Assistant ExaminerRonald H. Lazarus PP 198,629 Attorney-Tom Arnold et al.

52 US. Cl. ..308/4 A, 285/419 [571 R C Cl. ..F16c A novel latching mechanism is provided for a Fleld 285/373, 419, 42] pipe protector of the split ring type. The latch mechanism includes hook members located on the References Cited either side of the split, which are secured in place 1 around a drill string by a C-clip which slides longitu- UNITED STATES PATENTS dinally. Tabs on each end of the split permit ready 3,054,646 9/1962 Minor .f ..308/4 A longitudinal alignment of hook members for sliding of 1,938,822 12/1933 Ferlin ..308/4 A the C-cl ip into place, 3,129,982 4/1964 Fawick ..308/4 A 1,974,546 9/1934 Shipley ..308/4 A 5 Claims, 5 Drawing Figures DRILL PIPE PROTECTOR BACKGROUND OF THE INVENTION In drilling deep bore holes in the earth, such as in oil well drilling, the bore holes are usually of such depth that the metal drill string which carries the drill bit tends to whip laterally into abrasive engagement with the metal casing lining the bore hole. It is customary to prevent such abrasive metal-to-metal engagement between the drill string and well casing by means of a protector device secured about the drill string. Such protector devices are variously called drill pipe protectors or wear preventors. They usually comprise a sleeve or ring which is split on one side for attachment to the drill string. The sleeve includes an inner reinforcing member usually of metal and an inner and outer layer of elastic or yieldable material, such as rubber.

Such well protector devices are normally secured in frictional engagement around a drill string by means of a latching or retaining mechanism. It is customary to use a separate tool to contract the jaws of a protector device about a drill string. Then a pin, key or other latching device is put in place in the jaws of the protector device to retain the protector device in place.

SUMMARY OF THE INVENTION The present invention is directed to a novel and improved latching mechanism for a drill pipe protector. The unique construction and design of this latching mechanism permits ready longitudinal alignment of the sides of the drill pipe protector on either side of the split, ready for the application of the latching or retaining device. The latching mechanism, according to the present invention, includes hook members carried by the drill pipe protector on opposite sides of the split, each hook member being turned radially outward. A retaining member, which may be in the form of a C- shaped clip, bridges the split and holds the hook members to secure the drill pipe protector contracted about the drill string. The retaining means is slidable lengthwise along the hook members for attachment to and detachment from the drill pipe protector body. At least one tab is carried on one side of the drill pipe protector and extends beyond the edge of the hook member. A mating indentation carried by the other side of the drill pipe protector receives the tab to provide a ready means for longitudinal alignment of the hook members when the hook members are brought near to engagement with each other for application of the retaining means.

By use of the present invention, the installation and latching of drill pipe protectors around drill strings can be achieved faster and simpler than previously known in the art.

DESCRIPTION OF DRAWINGS The invention will now be described by way of a specific embodiment with reference to the accompanying drawing in which:

FIG. 1 is perspective view of a drill pipe protector embodying the invention;

FIG. 2 is sectional view taken along line 2-2 in FIG.

FIG. 3 is an enlarged view of the latching mechanism shown in FIG. 2;

FIG. 4 is an elevational view of the hook members taken along line 4-4 in FIG. 2; and,

FIG. 5 is a sectional view of the latching mechanism taken along line 5-5 in FIG. 1.

DESCRIPTION OF SPECIFIC EMBODIMENTS Referring to FIGS. 1 and 2, a drill pipe protector is shown secured in place around a portion of a drill string. The drill pipe protector comprises a cylindrical body 12 of yieldable material such as rubber in which is embedded a reinforcing cylindrical metal sleeve or band 14. A series of ribs 16 are formed around the circumference of the body 12 to provide the surfaces for bumping or rubbing against a metallic well casing (not shown). Between the ribs 16 are grooves or channels 18 through which the drilling mud circulating in the bore hole between the drill string and the casing is allowed to pass.

The metal band 14 is shown in the form of a solid cylindrical sleeve, but it may take many different forms. For example, the metal sleeve 14 may be shaped in a sinusoidal or corrugated shape. Band 14 may also be slotted or perforated in various manners and may be constructed of multiple components.

The drill pipe protector illustrated in FIGS. 1 and 2 includes on one side a split or gap in which is located a latching mechanism 20. This latching mechanism is opened when it is desired to place the drill pipe protector around a drill string.

As shown in FIGS. 3, 4 and 5, the latching mechanism, according to the present invention, includes hook members 22 and 24 which are formed of a rigid material such as metal and are turned radially outward. I-Iook members 22 and 24 may be carried by plates 26 and 28 which are secured to the opposite ends of the band 14. Under certain circumstances it may be desirable to have the hook members 22 and 24 comprised of the same strip of material as the band 14. Under other circumstances hook members 22 and 24 may be formed of separate plates which are bolted or otherwise secured to the band 14.

A detachable retaining means 28 is provided for engagement with the hook members 22 and 24. The retaining means 28 is shown in the form of a C-clip which slides longitudinally along the hook members. The retainer means 28 includes a crimped end portion 29 which abuts against the end of the hook members 22 and 24 to stop sliding movement.

Novel guide tabs 30 and 32 are carried by the plate member 28 secured to one side of the band 14. Guide tabs 30 and 32 are received by indentations 33 and 34 formed in the plate member 26 which is carried by the opposite side of the band 14. Tabs 30 and 32 permit ready alignment of the two sides of the band 14 for application of the retaining means 28 to the hook members 22 and 24.

The band 14, the hook members 22 and 24 and the retaining means 28 are preferably constructed of a soft metal of high tensile strength so that if the pipe protector becomes lodged in a well bore under adverse conditions, it can be pierced by an ordinary drill bit used in drilling the well bore.

Notice that in the embodiment shown retaining means 28 is protected within the extremities of the metal band 14. This arrangement is preferred in order to minimize the possibility that the retaining means 28 will be accidentally removed under adverse conditions in the well bore. In many state-of-the-art pipe protectors, latching pins protrude outside any protective bars, thus being exposed to being pried loose by mechanical objects in the well bore. With such state-of-the-art pipe protectors, latching pins are frequently pried loose in the well bore, thus allowing the pipe protector to come off the drill pipe and causing costly fishing jobs to remove.

Notice also that the entire latching mechanism is exposed to bare metal and not covered with rubber. In many existing pipe protectors on the market, the latching mechanism is covered with the rubber material that surrounds the entire body of the pipe protector. Therefore, should the latching pins be damaged in the well bore and not be removable by normal means, an acetylene cutting torch must be used to remove the pipe protector from the drill pipe, thus damaging the pipe protector for further use. In the embodiment of the invention shown in the drawings, a damaged and stuck retaining means 28 can be removed by a cutting torch without damaging the whole pipe protector.

By conventional practice a tensioning device or clamp is applied to contract the side of a drill pipe protector body about a drill string for application of a latching mechanism. As shown in FIG. 1 the drill pipe protector body includes a pair of indentations 40 and 42 respectively in ribs 16a and 16b. The tongs of such a tensioning device are located in indentations 40 and 42 to contract the drill pipe protector around a drill string and bring the hook members 22 and 24 into nearness with each other. The guide tabs 30 and 32 aid in iongitudinal alignment of the hook members 22 and 24. When longitudinal alignment is achieved, the retaining means 28 is engaged around the hook means at one end and slid longitudinaily onto engagement with the hook members.

As shown in FIG. 4 the guide tabs 30 and 32 each include one side 30a and 32a which is formed at an acute angle with respect to the longitudinal axis of the drill pipe protector body. This side with the acute angle is received in a corresponding and parallel side in indentations 33 and 34 by which the two sides of the latch mechanism are brought into longitudinal alignment.

The guide tabs illustrated in FIG. 4 are shown formed on the same side of the latching mechanism, but it will be understood that one guide tab may be formed on one side and one on the other in alternative embodiments. The guide tabs may take various shapes and forms depending upon the particular application.

Now that a specific embodiment of the invention has been described and illustrated, those skilled in the art may imagine still other embodiments still within the true spirit and scope of the invention. It is intended to cover all such embodiments that fall within the scope of the appended claims.

What is claimed is:

1. In a device for preventing wear between a drill string and a metal casing, said device including a cylindrical body of yieldable material with a gap on one side for application around a drill string, a rigid structural band being embedded in said body and being longitudinally split in said gap, the improvement comprising:

hook members carried by said structural band on opposite sides of said gap, said hook members being turned radially outward;

a retaining member bridging said gap and having hooked portions which engage inside said hook members to hold said cylindrical body contracted about a drill string, said retaining member being slidable lengthwise along said hook members for attachment to and detachment from said cylindrical body;

at least one tab carried by one side of said structural band at said gap and extending beyond said hook member;

an indentation carried by the other side of said structural band to receive said tab, said tab and indentation providing means for longitudinal alignment of said hook members when said hook members are brought near to each other for application of said retaining means.

2. The device according to claim 1 wherein said retaining member includes means for stopping the lengthwise movement thereof by abutment with one end of said hook members.

3. A device according to claim 1 wherein one of said tabs is located at each end of said hook members on one side of said gap and one of said indentations is located in a mating position at each end of the hook member on the other side of said gap.

4. A device according to claim 1 wherein said means for longitudinal alignment comprises one flat side of said tab positioned at an acute angle with respect to the longitudinal axis of said cylindrical body and a flat side of said indentation parallel to the flat side of said tab.

5. In a device for preventing wear between a drill string and a metal casing, said device including a cylindrical body of yieldable material with a gap on one side for application around a drill string, a metal band being embedded in said body and being longitudinally split in said gap, the improvement comprising:

hook members carried by such structural band on opposite sides of said gap, said hook members being turned radially outward;

a retaining member bridging said gap and having hooked portions which engage inside said hook members to hold said cylindrical body contracted about the drill string, said retaining member being slidable lengthwise along said hook members for attachment to and detachment from said cylindrical body, said retaining member including means for stopping the lengthwise movement thereof by abutment with one end of said hook members;

tabs carried by one side of said structural band at said gap at each end of said hook member, said tabs extending beyond said hook member, said tabs having one flat side positioned at an acute angle with respect to the longitudinal axis of said cylindrical body;

indentations carried by the other side of said structural band at said gap at each end of said hook member, said indentations being adapted to receive the corresponding tab, said indentations having one flat side parallel with the flat side of the corresponding tab, said tabs and indentations providing means for longitudinal alignment of said hook members when said hook members are brought near to each other for application of said retaining means. 

1. In a device for preventing wear between a drill string and a metal casing, said device including a cylindrical body of yieldable material with a gap on one side for application around a drill string, a rigid structural band being embedded in said body and being longitudinally split in said gap, the improvement comprising: hook members carried by said structural band on opposite sides of said gap, said hook members being turned radially outward; a retaining member bridging said gap and having hooked portions which engage inside said hook members to hold said cylindrical body contracted about a drill string, said retaining member being slidable lengthwise along said hook members for attachment to and detachment from said cylindrical body; at least one tab carried by one side of said structural band at said gap and extending beyond said hook member; an indentation carried by the other side of said structural band to receive said tab, said tab and indentation providing means for longitudinal alignment of said hook members when said hook members are brought near to each other for application of said retaining means.
 2. The device according to claim 1 wherein said retaining member includes means for stopping the lengthwise movement thereof by abutment with one end of said hook members.
 3. A device according to claim 1 wherein one of said tabs is located at each end of said hook members on one side of said gap and one of said indentations is located in a mating position at each end of the hook member on the other side of said gap.
 4. A device according to claim 1 wherein said means for longitudinal alignment comprises one flat side of said tab positioned at an acute angle with respEct to the longitudinal axis of said cylindrical body and a flat side of said indentation parallel to the flat side of said tab.
 5. In a device for preventing wear between a drill string and a metal casing, said device including a cylindrical body of yieldable material with a gap on one side for application around a drill string, a metal band being embedded in said body and being longitudinally split in said gap, the improvement comprising: hook members carried by such structural band on opposite sides of said gap, said hook members being turned radially outward; a retaining member bridging said gap and having hooked portions which engage inside said hook members to hold said cylindrical body contracted about the drill string, said retaining member being slidable lengthwise along said hook members for attachment to and detachment from said cylindrical body, said retaining member including means for stopping the lengthwise movement thereof by abutment with one end of said hook members; tabs carried by one side of said structural band at said gap at each end of said hook member, said tabs extending beyond said hook member, said tabs having one flat side positioned at an acute angle with respect to the longitudinal axis of said cylindrical body; indentations carried by the other side of said structural band at said gap at each end of said hook member, said indentations being adapted to receive the corresponding tab, said indentations having one flat side parallel with the flat side of the corresponding tab, said tabs and indentations providing means for longitudinal alignment of said hook members when said hook members are brought near to each other for application of said retaining means. 